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FreerdpApplication

CVE-2026-25959

CRITICAL · 9.8 CVSS v3.1 Published 2026-02-25
Fix available
A fix is available. Upgrade to 3.23.0 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `xf_cliprdr_provide_data_` passes freed `pDstData` to `XChangeProperty` because the cliprdr channel thread calls `xf_cliprdr_server_format_data_response` which converts and uses the clipboard data without holding any lock, while the X11 event thread concurrently calls `xf_cliprdr_clear_cached_data` → `HashTable_Clear` which frees the same data via `xf_cached_data_free`, triggering a heap use after free. Version 3.23.0 fixes the issue.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Heap use-after-free in FreeRDP's cliprdr (clipboard) channel where a race condition exists between the cliprdr channel thread using clipboard data via `xf_cliprdr_server_format_data_response` and the X11 event thread freeing the same data via `xf_cliprdr_clear_cached_data` → `HashTable_Clear` → `xf_cached_data_free`, causing concurrent access to freed memory.

MitigationUpgrade FreeRDP to version 3.23.0 or later which adds proper synchronization to prevent the race condition between threads accessing clipboard data.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
FreerdpApplication
Affected:< 3.23.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed FreeRDP version
    Run 'freerdp-version' or check your package manager for the installed freerdp package version
    Affected if Version is lower than 3.23.0 (e.g., 3.22.0, 3.16.0, etc.)
  2. Determine if cliprdr clipboard channel is in use
    Review FreeRDP connection parameters or server configuration for presence of /clipboard or cliprdr channel enablement
    Affected if Clipboard redirection (cliprdr) channel is enabled in the FreeRDP session
  3. Verify X11-based FreeRDP usage
    Confirm the FreeRDP client or server is running on an X11 window system (the vulnerability involves xf_ functions for X11)
    Affected if Operating in an X11 environment with FreeRDP clipboard integration active
  4. Check for concurrent clipboard access patterns
    Monitor for symptoms of the race condition during active clipboard operations between client and server
    Affected if The FreeRDP session involves clipboard data exchange (copy/paste operations) while the vulnerability is present

You are affected if running FreeRDP version below 3.23.0 with the cliprdr (clipboard) channel enabled in an X11 environment, as the race condition between clipboard access threads can trigger the use-after-free.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 3.23.0 or later
Fixed in 3.23.0
Vendor patch github.com →
Interim mitigation

Upgrade FreeRDP to version 3.23.0 or later which adds proper synchronization to prevent the race condition between threads accessing clipboard data.

Recommended fix High confidence

FreeRDP 3.23.0

  1. Identify the current FreeRDP installation method (package manager, source compile, Docker, etc.)
  2. For Linux systems using package managers: run 'apt-get update && apt-get upgrade freerdp' (Debian/Ubuntu) or 'yum update freerdp' (RHEL/CentOS)
  3. For systems compiling from source: download FreeRDP 3.23.0 or later from https://github.com/FreeRDP/FreeRDP/releases, rebuild and reinstall
  4. For Docker deployments: update the FreeRDP container image to a version containing 3.23.0 or later
  5. Verify the installed version using 'xfreerdp --version' to confirm the upgrade was successful
Caveat Minor version upgrade within 3.x series; likely minimal breaking changes but verify compatibility with your RDP server and any dependent client configurations

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Freerdp Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,808.

Scan for this in your stack

Free · runs locally
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-25959 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data